Sensirion once again proves to be a pioneer in innovation for environmental sensor solutions. The SCD40 represents the first CO₂ and RH/T sensor in miniature format, which impresses with a space requirement of only one cubic centimeter. This disruptive innovation is based on the photoacoustic measurement principle and combines minimum size with maximum performance. This opens up numerous new possibilities for integration and applications. Due to its unparalleled price/performance ratio, the SCD40 is particularly suitable for series production and cost-sensitive applications.

Increasing environmental awareness not only affects the way people live, travel and eat, but also the design of buildings. Modern houses strive for very high energy efficiency in order to save natural resources, which are mainly used for heating. One consequence of this is the trend towards airtight buildings, which have better insulation than older buildings. Airtight buildings mean that there is less air exchange through walls, roofs, windows, cracks, etc., which has a negative effect on the air quality inside. Reduced indoor air quality in turn negatively affects people’s productivity and well-being – ultimately requiring an active ventilation system that provides regular fresh air for a healthy and productive indoor climate. Since ventilation systems require large amounts of energy to condition and provide fresh air, it is important to ensure that the systems are highly energy efficient, which is made possible by ventilation strategies that control air exchange based on current demand.

Humans are the main source of indoor contamination, so the need for fresh air depends on the number of people present in a room and their activities (e.g. cooking, sports, recreation). Based on the measurement of indoor air quality, a demand-oriented air exchange can be enabled, which on the one hand ensures a healthy and comfortable environment and on the other hand guarantees a high energy efficiency. Energy-efficient here means that the amount of air that needs to be introduced into the house and conditioned (e.g. cooled, heated, filtered) is kept to a minimum. People exhale carbon dioxide oxide (CO₂) depending on their activity and physiological factors (age, sex, weight, etc.). If there are people in closed buildings, the CO₂ concentration in this room will increase and the indoor air quality will decrease. This allows the CO₂ concentration to be used as an indicator of air quality and as a control parameter for ventilation systems.

Sensirion revolutionizes the market for CO₂ sensors with the new SCD40 sensor, which is based on Sensirion’s unique PASens® technology. The PASens® technology uses the photoacoustic measurement principle and offers extreme miniaturization of the CO₂ sensor without compromising sensor performance. This is because the sensitivity of the sensor is independent of the size of the optical cavity, in contrast to the NDIR measurement principle commonly used today. This enables customers to integrate the sensor in a cost-efficient, flexible and compact way and allows the use of CO₂ sensors in applications where previously there was not enough space available. In addition, the number of integrated electrical components has been drastically reduced, resulting in an extremely price-efficient cost structure and thus significantly lower prices. The new SCD40 now allows customers to integrate CO₂ sensors in cost-sensitive applications and in large quantities. The miniaturization of the sensor and the attractive cost structure open up numerous new possibilities for the SCD40 to be integrated into new products and applications with high volumes, such as compact ventilation systems, air exchangers, air duct probes, air purifiers, thermostats, air conditioning units and air quality monitors.